The tall, beautiful iris plant is named after the Greek goddess Iris who is the goddess of the rainbow. Despite being of divine origin, growing iris flowers is easy, rugged, and reliable.
In this post, I have described how to grow and care for Iris flowers in detail. After reading this article I guarantee you’ll be able to grow bright and colorful iris flowers by yourself.
So, let’s dive into:
How Iris plant looks like
They have six petals and three outer hanging petals and three inner upright petals on the flower.
source: Jett Brooks
There are around 300 species that belong to the iris genus, and most of the species are tall at least 26 inches in height.
Iris can be a bearded type or breadless (crested). Bearded iris bulbs have soft long hair along the center in the falls, breadless iris bulbs have hairs that form ridge or comb.
Mostly iris blooms in early summer. However, some bearded iris also blooms in late summer.
This popular flowering plant is available in many colors and attracts beautiful pollinators like butterflies, bees, and hummingbirds. They are used as ornamental flowers that look wonderful in vases.
Roses, peonies, and lilies are some great companion plants for the iris in the garden.
When to plant
Plant them between early summer to early fall, this gives them plenty of time to get established before winter. Plant at night when the temperature is, between 40 to 50 Fahrenheit or above.
If you’re growing tall bearded iris flowers then plant closer to fall, as they go dormant in the early to mid-summer.
If you receive bare roots iris bulbs in the container do not wait for the perfect time. It’s better to plant them in the ground rather than wait for a convenient time.
Where to plant iris plant
Iris flowers love to grow in full sunlight, plant them where they receive at least half a day of sunlight. If they do not get enough sunlight they will not bloom.
If you’re planting bearded iris make sure the plant does not get shaded out with other plants; Many do best when providing a special soil bed of their own.
How to plant iris bulbs in the ground
Prepare the soil bed two weeks before by losing soil up to 10-12 inches deep to establish good drainage. While preparing you can also mix organic matter.
source: Linda Tanner
Plant the bare root of the plant horizontally to the soil surface. In the hot climate, plant rhizomes are just below the soil surface.
The rhizomes should be planted in such a way that they are slightly visible on the soil surface or thinly covered in the warmer climate.
Plant rhizomes in a single or group with at least 1 foot of gap between each. If you plant too close it will cause problems when they mature.
Do not plant iris rhizomes too deep in the soil. If you plant rhizomes too deep they will not bloom. Also do not spread mulch around rhizomes, this practice may cause rot.
After planting, water thoroughly in the beginning plant needs more water to get established.
How to grow iris plants in pots
Although it’s not common you may grow iris plants in the container; the size of the container or pot should be at least 12 inches wide.
- The container or pot should have adequate holes, for good drainage.
- Consider putting rocks or stones in the bottom of the pot for good drainage and air circulation.
- Use loose, potting mix soil for good growth; sow the plant in the soil slightly, leaving the top rhizomes exposed.
- After planting water thoroughly till water starts falling from the bottom.
- Do not over water, in the pot overwatering is an issue; consider watering when the upper surface of the soil looks dry, as the plant is drought tolerant water only once or twice a week.
- In the winter, bring the pot inside to overwinter, it might die if not given shelter in the cold winter.
- You have to divide and transplant more frequently in pots as compared to ground, maybe every other year or so.
In the pot, the rhizomes have limited space to spread, so you have to prune them occasionally to maintain an ideal shape.
How to Care for an Iris Plant
source: Bernard Fidel
Light
Sunlight is very important in iris growth, if the plant does not get enough light it will not bloom. Plant them in a spot which receives maximum sunlight.
Water
Although iris plants like moisture, good drainage is essential to prevent rot problems. Do not let the plant stand in water, iris plants should be water only when 2 inches of the soil surface look dry.
These plants are water tolerant and survive without water for a longer time.
Soil
They grow best in sandy or gravelly soil, heavy clay soil does not work well for growing iris.
If your native soil is heavy you can plant it in the raised bed to help drainage. You can also amend native soil with gypsum or organic matter like compost to make the soil lighter.
Temperature and humidity
Most iris plants do not mind temperature extremes, till there is excessive rain or heavy snowmelt to drain roots. This plant is mostly damaged by heavy winds or hails and can be susceptible to borer larvae entering the plant.
Fertilizer
In the spring, feed them with low-nitrogen 6-10-10 fertilizer around the plant. You can also add a bone meal. Feeding once a month with too much fertilizer will encourage more growth of foliage rather than blooms.
Pruning
If you want your plant to bloom regularly, you have to prune it regularly.
When the iris blooms, take flower cuttings and decorate in the vase or you can also let them hang on branches for garden beauty.
Always cut the branch where the flower has bloomed. Cut all dry flowers or foliage from the stem, these dry parts look dead but they keep sucking energy from the plant. When you snip off them the energy will redirect to grow new leaves and flowers.
How to divide Iris bulbs
You need to divide the iris plant usually after every 2-3 years. Over time, the iris plant becomes overcrowded and stops blooming, this happens when rhizomes lose vitality and nutrients from the soil.
source: Jennifer Rafieyan
When this happens you need to divide and transplant them in fresh soil for continuous growth.
Here is what to do:
- Toss out the plant from the ground with its rhizomes, you will notice that the plant’s rhizome (called mother rhizomes) has developed several offspring rhizomes.
- Separate offspring rhizomes from the mother rhizomes with a shape knife.
- Cut the bottom of these rhizomes with shear to make visible fresh white tissue.
- Keep cutting till you get fresh tissue, if there is any spot on the end throw it, cause it is infected and will not grow properly.
- Destroy or throw rhizomes that look infected or have dark-brown spots on them.
- Prepare rich soil bed for selected rhizomes, and snip off 5-6 inches of leaves from the bottom of the cutting, so that new roots would able to thrive
- You can make these cutting stands on a new soil bed, transplant them in a new spot, or gift them to friends and family to spread iris joy.
- These iris cutting will grow individually and become similar to parent plants.
Pest and diseases
Iris bulbs are often attacked by some pests like verbena bud moth, whiteflies, iris weevil, aphids, thrips, slugs, snails, and sometimes nematodes may also bother the plant.
You can occasionally apply organic oil to control these pests to some extent like neem oil on the stem.
They are deer-resistant and drought-tolerant. However, these plants are susceptible to horrible iris borer which like to overwinter eggs on the leaves. If you notice vertical streaks on the leaves, then find these pests and squash them.
If you see your plant foliage turning yellow-brown it’s a sign of rot root, stop overwater or if the problem is savior, you have to dig it up and remove the infected parts.
Toxicity
Iris bulbs are toxic to cats and dogs, especially rhizomes, if you have pets in the house do not plant them or take care that your pets are not ingested. The plant contains resinous purgative and irisin and cytotoxic terpenoids that cause vomiting, diarrhea, and drooling and sometimes lead to death.
If your pet shows these signs take them to an animal doctor in no time; treatment may include inducing vomiting or giving active charcoal to the pet.
Recommended varieties
source: Liz west
Here are some popular iris varieties that you can grow in your garden.
The tall bearded varieties come in flamboyant colors that generally bloom in June month. They are June bloomers and are usually planted only in the fall.
Some tall varieties:
“Immortality” is a tall bearded variety that blooms in June and then offers a second crop of white spring in the late summer. They are hardy in zone 4.
Other varieties that are hardy in zone 4 are “FeedBack”, a dark purple; “I Do”, with white flowers, and “Earl of Essex”, with purple flowers.
For zones above 5 or warmer, try “Jennifer Rebecca”, a mauve pink beauty.
“Siberian Iris” is available in many colors. They have more delicate beauty than the stately breaded variety but are equally rugged.
“Japanese iris” are special types of varieties that thrive around the ponds. And has huge flat blooms.
Did I Miss Anything?
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Before going if you want to grow beautiful flowers in your garden? Then click on these articles also.
Hey! I’m Madhuresh, a passionate content creator, and a Plant lover. I created Shiny Plant to explore and learn about new plants. The purpose is to provide simple and effective Gardening Tips. Hope you’ll find this informative.